Supermicro SSE-G2252, User Manual

Page: 189 / 1401

Chapter 8: Spanning Tree Algorithm
Configuring Global Settings for STA
– 193 –
Figure 8-4: Configuring Port Loopback Detection
C
ONFIGURING
G
LOBAL
S
ETTINGS FOR
STA
Use the Spanning Tree > STA (Configure Global - Configure) page to
configure global settings for the spanning tree that apply to the entire
switch.
CLI R
EFERENCES
•
“Spanning Tree Commands” on page 1021
C
OMMAND
U
SAGE
•
Spanning Tree Protocol
1
This option uses RSTP set to STP forced compatibility mode. It uses
RSTP for the internal state machine, but sends only 802.1D BPDUs.
This creates one spanning tree instance for the entire network. If
multiple VLANs are implemented on a network, the path between
specific VLAN members may be inadvertently disabled to prevent
network loops, thus isolating group members. When operating multiple
VLANs, we recommend selecting the MSTP option.
•
Rapid Spanning Tree Protocol
1
RSTP supports connections to either STP or RSTP nodes by monitoring
the incoming protocol messages and dynamically adjusting the type of
protocol messages the RSTP node transmits, as described below:
•
STP Mode – If the switch receives an 802.1D BPDU (i.e., STP BPDU)
after a port’s migration delay timer expires, the switch assumes it is
connected to an 802.1D bridge and starts using only 802.1D
BPDUs.
•
RSTP Mode – If RSTP is using 802.1D BPDUs on a port and receives
an RSTP BPDU after the migration delay expires, RSTP restarts the
migration delay timer and begins using RSTP BPDUs on that port.
•
Multiple Spanning Tree Protocol
1. STP and RSTP BPDUs are transmitted as untagged frames, and will cross any VLAN
boundaries.